1. On March 11, 1913, the Great Dayton Flood began, resulting in one of Ohio's deadliest natural disasters. Heavy rainfalls caused the Great Miami River and its tributaries to overflow, flooding the city of Dayton and surrounding areas. The flood claimed the lives of over 360 people and caused millions of dollars in damage.

2. The Ohio House of Representatives passed a law on March 11, 1964, prohibiting racial discrimination in housing. Known as the Ohio Civil Rights Law, the legislation barred landlords from refusing to rent or sell to individuals based on their race, religion, or national origin.

3. The Ohio Supreme Court issued a landmark decision on March 11, 1999, overturning the state's ban on gay adoptions. The court ruled that the state's policy of forbidding gay individuals and couples from adopting children was discriminatory and violated the equal protection clause of the Ohio Constitution.

4. On March 11, 1943, the United States and Great Britain signed the Lend-Lease agreement with the Soviet Union, allowing the USSR to receive military and economic aid during World War II. Ohio played a crucial role in the war effort, with industrial hubs like Cleveland and Dayton producing weapons and equipment for the US military.

5. The Ohio Department of Natural Resources opened the Beaver Creek Wildlife Education Center on March 11, 1988. The center, located near the town of East Liverpool, offers hiking trails, wildlife exhibits, and educational programs highlighting Ohio's natural resources and ecology.